Aqua Hot Help

[Mike&Chris]

We r camping in cold weather (high 29) and my aqua hot burner randomly quits firing up. I went to bed and all was good, awoke around 3 to a cold coach. Turned the burner on and off and it fired up and ran fine. It’s done that several times. It was last serviced January 18 and hasn’t been used very much as we try to avoid cold weather. Is there something lease I might check?

[Magic-carpet]

Originally Posted by Mike&Chris

We r camping in cold weather (high 29) and my aqua hot burner randomly quits firing up. I went to bed and all was good, awoke around 3 to a cold coach. Turned the burner on and off and it fired up and ran fine. It’s done that several times. It was last serviced January 18 and hasn’t been used very much as we try to avoid cold weather. Is there something lease I might check?

How well was it working before you had it serviced? Are there any red lights on the control panel? First thing I would check would be the wiring and make sure all the plugs are seated well on the control board and the control module. Also check the safety interlock on the cover. Jumper it over with the cover off. Is it blowing white or black smoke on startup? And of course the obvious. Is there plenty of fluid in the overflow tank?

[royals1212]

Check your fluid level. When pumping fluid thru the heating loops sometimes you will have air bubbles and cut drop your fluid just enough for the low fluid cut off switch to open

[Victory Blue]

If it’s been a year it needs service, even if it was working normally.

It’s critically important to run the diesel burner monthly, at least one full cycle. Personally, I think letting it run for a full day is even better. Not running it regularly will eventually cause the nozzle to become plugged and the fuel filter to restrict the fuel flow and it won’t be there when you need it.

It’s also good practice to run the Aquahot pumps by turning the heat on monthly.

[Fattman-Litlboy]

Originally Posted by Victory Blue

If it’s been a year it needs service, even if it was working normally.

It’s critically important to run the diesel burner monthly, at least one full cycle. Personally, I think letting it run for a full day is even better. Not running it regularly will eventually cause the nozzle to become plugged and the fuel filter to restrict the fuel flow and it won’t be there when you need it.

It’s also good practice to run the Aquahot pumps by turning the heat on monthly.

Absolutely right. It's the old phrase, "Use it, or lose it!" We run ours whenever we shower, or when it's cold below 40°. We're full timers now for 4-yrs and have never had an issue except for the common pump replacements. Service it once a year, and use it frequently!
Jim

[Fattman-Litlboy]

That also includes running all three zones at least monthly, not just the hot water stir pump#3 for showers.
Jim

[voltdoc]

When it quits, does the light go out on the burner switch? Then flick the switch off and on and the burner starts up again? Mine was doing that randomly and got progressively worse. There were no errors on the status panel, so I believe this symptom indicates a burner fault.

Replacing the filter and nozzle and cleaning off the flame sensor resolved the issue for me. You can get a filter and nozzle on Amazon for about $20 with shipping. Use brake cleaner to clean the flame sensor and other parts.

I suspect it was the very sooty flame sensor that was the reason for the burner fault in my case. In the photo that's the rectangular unit at the bottom of the circular disc, it should be whiteish and the circuitry should be visible. This photo is before any cleaning was done. It looks like I also had a nozzle leak or drippy nozzle at some point based on the stains seen on the disk.

[Mike&Chris]

Thanks guys, I suspect the issue is lack of use in warm months. I did not know it required monthly use like the generator.

Does anyone have instructions on repacking the nozzle and filter?

Thanks

[Victory Blue]

Originally Posted by Mike&Chris

Thanks guys, I suspect the issue is lack of use in warm months. I did not know it required monthly use like the generator.

Does anyone have instructions on repacking the nozzle and filter?

Thanks

Mike,

I can send you a video, done at Quartzsite in 2017, showing the whole service process; it’s a very good video. Send me a private message with an email address and I’ll send it to you. I don’t see a way to attach a video to a private messsage sent through the forum.

[lwmcguire]

A bad coil will give similar symptoms if the filter and nozzle exchange doesn't fix the issue

[KCBless]

Originally Posted by Mike&Chris

We r camping in cold weather (high 29) and my aqua hot burner randomly quits firing up. I went to bed and all was good, awoke around 3 to a cold coach. Turned the burner on and off and it fired up and ran fine. It’s done that several times. It was last serviced January 18 and hasn’t been used very much as we try to avoid cold weather. Is there something lease I might check?

We did have the same issue with ours that was fixed at our 2 year PDI. I think they replaced the controller board.

It would seem to be running fine initially but once it turned the burner off because of lack of demand, it would not restart the burner unless I cycled the Aquahot on and off.

[oneknight]

Originally Posted by KCBless

We did have the same issue with ours that was fixed at our 2 year PDI. I think they replaced the controller board.

It would seem to be running fine initially but once it turned the burner off because of lack of demand, it would not restart the burner unless I cycled the Aquahot on and off.

Mine had a similar symptom, it was a bad thermostat in the aquahot.

[Mike&Chris]

Thanks everyone for your help.

[voltdoc]

Originally Posted by Mike&Chris

Does anyone have instructions on repacking the nozzle and filter?

Thanks

The service manual on the Aquahot website gives a step by step. Also I found these two articles to have some useful tips even tho the procedure has changed somewhat for the newer units:

Aquahot and Hydrohot Annual Service

https://www.rvtechmag.com/tech/38_aquahotsvc.php

Note the newer models like yours have metal fuel lines internal to the AH case. I just did the nozzle/filter/cleaning a couple of weeks ago. You will need:

• Filter - Generalaire 2605 Model "R" Gar-Ber Epoxy Spin-On Oil Filter Cartridge or equivalent. (Aqua-Hot Part FLE-120-100)
• Nozzle - Danfoss 030F6103 0.35 GPH 60° S Oil Nozzle (Aqua Hot Part WPX-886-41A)
• Gasket - AquaHot Part HDE-700-205 (If you are going to remove the burner tube and clean the soot)
• Hose pinchers
  
• A 1/4" or 3/8" socket set
• A torque wrench that reads as low as 20-40 INCH pounds if you are afraid of breaking the burner toggle ears (expensive repair if you do).
• Brake Cleaner